Before typing the number beginning with zero, convert that cell format to
text (Format--> Cells-->Number--> select Text in the list) otherwise begin
with ' (single quote) and then type the number ('012345).
I am guessing that you are in the UK or somewhere where phone numbers do
begin with zero. I wish Uncle Bob would realize that phone numbers are
actually not calculable, and are, therefore, codes, and should be
allowed to be texted. just as area codes are CODES, formatted to be all
numeric. duh!!